This application is based on Japanese Patent Application No. 11-244174 (1999) filed Aug. 31, 1999, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a superconductive magnetic levitation transportation system, more specifically to a superconductive magnetic levitation transportation system which performs short to long distance transportation of cargoes such as mails, foods, or the like with saved energy and without causing pollution by using superconductive magnetic levitation for utilizing potential energy as a drive source of a transportation vehicle.
2. Description of the Related Art
Heretofore, methods for transporting mails or foods perform the transportation in the air, on the roads or rails utilizing airplanes, ships, automobiles, railways, and the like.
In such conventional transportation methods, since transportation is performed in the air, on the roads or rails while bearing large amounts of loss, there are required large amounts of fuel costs and labor costs, as well as substantial production costs of the transportation vehicles, furthermore, there are substantial effects on the environmental degradation.
Since prior art methods for transporting a cargo by airplanes, ships, or automobiles utilize petroleum as drive energy, they considerably tend to have adverse effects on the environment such as emission of hazardous substances by exhaust gases, acceleration of the global warming phenomenon by generation of CO2, air pollution by abrasion dust of tires. Further, for railways, a great importance is attached to environmental pollution due to nuclear power generation and thermal power generation for producing the electric energy. Still further, each of these transportation methods is very large in air drag loss for traveling in the air and frictional loss, and dissipates a large amount of petroleum which is concerned about its storage amount in the future.
With the aim of solving the above-described prior art problems, it is an object of the present invention to provide an energy-saving superconductive magnetic levitation transportation system which uses high-temperature superconductive magnetic levitation, which is extremely small in bearing loss, for non-contact levitation of a transportation vehicle, making a transportation passage in which the transportation vehicle travels to a vacuum or a reduced pressure atmosphere in order to remarkably reduce air drag loss, to reduce the drag during traveling to nearly zero, thereby supplying almost of the traveling drive force by the potential energy.
A yet further object of the present invention is to provide an energy-saving superconductive magnetic levitation transportation system which enables large-capacity transportation by connecting or providing a plurality of small-capacity transportation vehicles.
To accomplish the above objects, in a superconductive magnetic levitation transportation system according to the present invention, a transportation vehicle having a transportation cabin containing transportation cargoes is non-contactingly levitated by utilizing the pinning effect which is one of superconduction phenomena, traveled on a rail provided with permanent magnets or electromagnets in a traveling direction disposed in a vacuum transportation passage provided with a level difference between a start location and a destination location, and stopped at the destination location by absorbing traveling kinetic energy with potential energy when, approaching the destination location.
Further, for loading and unloading the transportation cargoes and performing other works, the start location and the destination location are provided with vacuum doors capable of closing a transportation pipe end (stop location of the transportation vehicle), and inside of which has a structure capable of being opened to the atmosphere and made to a vacuum. Still further, potential energy corresponding to the loss generated during traveling can be recovered by carrying the transportation vehicle to a high position utilizing an elevator and the like.
According to an aspect of the present invention, there is provided a superconductive magnetic levitation transportation system, comprising:
a transportation vehicle provided with a transportation cabin loading a transportation cargo, a first magnetic levitation member including a superconductive member, and a first coupling coil;
a magnetic levitation guide, having a second magnetic levitation member including a magnet opposing to the first magnetic levitation member and a second coupling coil magnetically coupled with the first coupling coil, for levitating the transportation vehicle; and
a transportation passage surrounding the transportation vehicle and the magnetic levitation guide in a vacuum or a reduced pressure atmosphere and disposed to have a level difference;
wherein the transportation vehicle is levitated on the magnetic levitation guide by the superconductive pinning effect of the first magnetic levitation member of the transportation vehicle and the second magnetic levitation member of the magnetic levitation guide so that the transportation vehicle is traveled by potential energy according to the disposition of the transportation passage, and the transportation vehicle is stopped driving, held or positioned by the first coupling coil of the transportation vehicle and the second coupling coil of the magnetic levitation guide.
Here, the transportation vehicle preferably comprises a cold accumulator disposed in close contact with the superconductive member and a refrigerator or a coolant for cooling the cold accumulator.
The magnet may be a plurality of permanent magnets disposed along the magnetic levitation guide in a traveling direction with the same magnetic polarities.
Further, the magnet may be a plurality of electromagnets disposed along the magnetic levitation guide in the traveling direction.
Still further, the superconductive member is preferably a high-temperature superconductor having a strong pinning force (high critical current density), for example, an yttrium type oxide superconductor (YBa2Cu3Ox) or a samarium type oxide superconductor (SmBa2Cu3Ox).
Yet further, the transportation vehicle may comprise the first magnetic levitation member and the first coupling coil disposed on one side with respect to the levitating direction and further a third magnetic levitation member and a third coupling coil disposed on the other side, and the magnetic levitation guide may comprise the second magnetic levitation member and the second coupling coil opposing to the first magnetic levitation member and the first coupling coil of the transportation vehicle, and a fourth magnetic levitation member and a fourth coupling coil opposing to the third magnetic levitation member and the third coupling coil of the transportation vehicle.
Yet further, the transportation vehicle may further comprise a fifth magnetic levitation member and a fifth coupling coil on a side to which a centrifugal force is applied where the transportation passage is bent, the magnetic levitation guide may further comprise a sixth magnetic levitation member opposing the fifth magnetic levitation member of the transportation vehicle.
Yet further, the transportation vehicle preferably has connection parts having a superconductor at one end with respect to the traveling direction and a magnet at the other end, and a plurality of the transportation vehicles may be connected by the connection parts.
Yet further, the transportation passage preferably further has at opposite ends a start area and an arrival area partitioned by vacuum doors.
Yet further, there may be provided a second magnetic levitation guide disposed to be connected or branched to the magnetic levitation guide such that potential energy of an arrival area of the second magnetic levitation guide is different from that of the magnetic levitation guide.
As described above, with the present invention, a large-capacity transportation can be possible by using high-temperature superconductive magnetic levitation in the bearings of the transportation vehicle to achieve high efficiency with remarkable reduction of bearing loss, and by connecting a plurality of small-capacity transportation vehicles.
According to the present invention, by achieving a high-efficiency and high-capacity superconductive magnetic levitation transportation system, since external driving power is almost unnecessary and there is almost no environmental pollution, the transportation system can greatly contribute to energy saving and solution of environmental problem.
Further, according to the present invention, it is possible to increase the natural frequency of each of the transportation vehicles and, since the kinetic energy of each transportation vehicle is not so large, when a malfunction occurs, energy can be dispersed and distributed, thereby minimizing effects on other system or peripheral apparatus.